

html,body{
    margin: 0;
    padding: 0;
}
img{
    width: 100%;
}

main{
    width: 750px;
    height: 900px;
    margin: 0 auto;
}
.bj{
    height: 100%;
    width: 100%;
    background: url("../bj.png");
    background-size: 100%;
}
.dx{
    width:40%;
    height: 30%; 
    margin: 0 auto;
    position: relative;
    top: 50px;
    left: 0;
}
.qd{
    width: 70%;
    margin: 0 auto;
    position: relative;
    top: 240px;
    left: 0;
}
.xz{
    width: 70%;
    margin: 0 auto;
    position: relative;
    top: 300px;
    left: 0;
}

@media screen and (min-width: 0px) and (max-width: 320px){
    main{
        width: 320px;
        height: 568px;
    }
}
@media screen and (min-width: 320px) and (max-width: 360px){
    main{
        width:  360px;
        height: 640px;
    }
}

@media screen and (min-width: 375px) and (max-width: 414px){
    main{
        width:  414px;
        height: 736px;
    }
.qd{
    width: 70%;
    margin: 0 auto;
    position: relative;
    top: 200px;
    left: 0;
}
.xz{
    width: 70%;
    margin: 0 auto;
    position: relative;
    top: 250px;
    left: 0;
}
}
@media screen and (min-width: 417px) and (max-width: 768px){
    main{
        width:  768px;
        height: 1024px;
    }
    .qd{
    width: 70%;
    margin: 0 auto;
    position: relative;
    top: 300px;
    left: 0;
}
.xz{
    width: 70%;
    margin: 0 auto;
    position: relative;
    top: 400px;
    left: 0;
}

}
@media screen and (min-width: 768px) and (max-width: 1024px){
    main{
        width:  1024px;
        height: 1366px;
    }
.qd{
    width: 70%;
    margin: 0 auto;
    position: relative;
    top: 350px;
    left: 0;
}
.xz{
    width: 70%;
    margin: 0 auto;
    position: relative;
    top: 450px;
    left: 0;
}
}
